Microelectromechanical systems (MEMS) technology is widely used in inertial navigation sensors as a miniaturized and low-cost solution. In conventional systems, displacement of a vibrating proof mass, which is directly proportional to rotation or acceleration, is sensed electrostatically. Electrical readout, such as capacitive sensing, is used in conventional practice. Electrical readout suffers from crosstalk of moving mass excitation circuit and noise pickup from harsh environment. These effects make significant portion of an error signal and thus degrading sensor performance. Further, the change of capacitance in conventional gyroscopes is small.
For the reasons stated above and for other reasons stated below, it will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for a MEMS device such that the displacement in the vibrating proof mass can be determined through optical sensing.